Skeletal, cardiac, and respiratory muscle function and histopathology in the P448Lneo- mouse model of FKRP-deficient muscular dystrophy.

BACKGROUND: Fukutin-related protein (FKRP) mutations are the most common cause of dystroglycanopathies known to cause both limb girdle and congenital muscular dystrophy. The P448Lneo- mouse model has a knock-in mutation in the FKRP gene and develops skeletal, respiratory, and cardiac muscle disease. METHODS: We studied the natural history of the P448Lneo- mouse model over 9 months and the effects of twice weekly treadmill running. Forelimb and hindlimb grip strength (Columbus Instruments) and overall activity (Omnitech Electronics) assessed skeletal muscle function. Echocardiography was performed using VisualSonics Vevo 770 (FujiFilm VisualSonics). Plethysmography was performed using whole body system (ADInstruments). Histological evaluations included quantification of inflammation, fibrosis, central nucleation, and fiber size variation. RESULTS: P448Lneo- mice had significantly increased normalized tissue weights compared to controls at 9 months of age for the heart, gastrocnemius, soleus, tibialis anterior, quadriceps, and triceps. There were no significant differences seen in forelimb or hindlimb grip strength or activity monitoring in P448Lneo- mice with or without exercise compared to controls. Skeletal muscles demonstrated increased inflammation, fibrosis, central nucleation, and variation in fiber size compared to controls (p < 0.05) and worsened with exercise. Plethysmography showed significant differences in respiratory rates and decreased tidal and minute volumes in P448Lneo- mice (p < 0.01). There was increased fibrosis in the diaphragm compared to controls (p < 0.01). Echocardiography demonstrated decreased systolic function in 9-month-old mutant mice (p < 0.01). There was increased myocardial wall thickness and mass (p < 0.001) with increased fibrosis in 9-month-old P448Lneo- mice compared to controls (p < 0.05). mRNA expression for natriuretic peptide type A (Nppa) was significantly increased in P448Lneo- mice compared to controls at 6 months (p < 0.05) and for natriuretic peptide type B (Nppb) at 6 and 9 months of age (p < 0.05). CONCLUSIONS: FKRP-deficient P448Lneo- mice demonstrate significant deficits in cardiac and respiratory functions compared to control mice, and this is associated with increased inflammation and fibrosis. This study provides new functional outcome measures for preclinical trials of FKRP-related muscular dystrophies.

Expression of serum TK1 in human breast tumor and its clinical significance / 中国癌症杂志

Background and purpose: The position of thymidine kinase 1 (TK1) expression during cell division is in the cytoplasm. It is a catalytic enzyme to convert deoxythymidine into thymidylate. It is the key enzyme of pyrimidine salvage pathway. The aim of this study was to analyze the serum expression level of TK1 in patients with breast cancer, and explore the application of serum TK1 test in clinical assessments of diagnosis, treatment and prognosis for breast cancer. Methods: Patient data were collected from the patients admitted in Comprehensive Breast Health Center at Rui Jin Hospital. Chemiluminesence dot blot assay was used to detect serum TK1 levels in 145 breast cancer patients and 55 patients with breast ifbroadenoma. The correlations of serum TK1 levels with breast tumor biological behavior was further studied. Results:Serum TK1 expression levels was signiifcantly increased in breast cancer patients [(2.749±0.122)pmol/L] when compared to breast fibroadenoma patients[(1.319±0.126)pmol/L, P0.05), different tumor grades (P=0.453) and different tumor size (P=0.908). Preoperative imaging results including breast ultrasound, breast mammography and breast magnetic resonance were analyzed by assessments of BI-RADS category, and serum TK1 levels in patients with different BI-RADS categories were studied. Serum TK1 levels in patients with breast ultrasound BI-RADS categories 4C-6 were signiifcantly higher than those with category 0-4B (P0.05). Most patients were followed up in our outpatient department for about 2 years. No progression-free survival differences were found in 2years. Conclusion:Serum TK1 test might be a potential tool for screening, prognosis determination and effect evaluations of targeted therapy in breast carcinoma.